Ink ribbon cartridge having a particular spool and spindle arrangement

ABSTRACT

The invention provides an ink ribbon cartridge which ensures proper, reliable mounting of an ink ribbon. The ink ribbon cartridge of the invention includes a pair of spools, an ink ribbon including a band-like sheet wound around the pair of spools and provided with a layer of ink formed on one surface thereof, four spindles which have disk-shaped sections at one end and can be placed, for a specific length in both ends of the pair of spools, and a cover covering the pair of spools around which the sheet is wound and having four round holes in which the disk-shaped sections of each of the spindles are loosely fitted. In one of the four ends of the pair of spools, only the other end of a specific one of the four spindles can be inserted for a specific length, and one of the four round holes formed in the cover is formed such that only the disk-shaped section on one side of the specific spindle can be loosely fitted.

More than one reissue application has been filed for reissue of U.S.Pat. No. 6,161,972. In particular, two applications for reissue havebeen filed: Reissue Application No. 10/323,062, filed Dec. 19, 2002 (nowU.S. Pat. No. RE39,169, issued Jul. 11, 2006 ), and the present reissueapplication, which is a continuation thereof.

This is a Continuation of application Ser. No. 08/990,732 filed Dec. 15,1997, now U.S. Pat. No. 5,913,621 issued Jun. 22, 1999. The entiredisclosure of the prior application is hereby incorporated by referenceherein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to an ink ribbon cartridge containing areplaceable wide ink ribbon.

2. Description of Related Art

Generally an ink ribbon cartridge is used because of its simplicity ofhandling when a thermal printer is used to print on common printingpaper. However, when a thermal printer (e.g., a line printer) uses alarge ink ribbon cartridge, it becomes uneconomical if the wholecartridge thrown away after use. To obviate this drawback, the inkribbon alone is replaced.

For this type of ink ribbon, there is employed an ink ribbon including aband-like sheet comprising a resin film with a layer of ink formed onone side of the ribbon and wound around a pair of paper spools. A priorart ink ribbon cartridge using this type of ink ribbon was constructedsuch that, at the time of ink ribbon replacement, the cover is opened,the used ink ribbon is taken out, and four spindles inserted in bothends of a pair of paper spools of the ink ribbon are removed and thenplaced in both ends of one pair of paper spools of a new ink ribbon.After the insertion of the new ink ribbon into the cover, the cover isclosed. Subsequently, the ink ribbon cartridge is mounted in a printeror a facsimile system as supported by a spindle on bearings thattransmit the torque to the paper spools through the spindles, therebywinding the sheet around the paper spool.

However, the above-described prior art ink ribbon cartridge is of such astructure that any one of the four spindles can be inserted into eitherof both ends of a pair of paper spools. In addition, in any combinationof spindles and spools, the ink ribbon is inserted into the cover toallow the cover to close. Therefore, failures in printing due toimproper mounting of the ink ribbon often occurred.

That is, since a layer of ink is formed on one side of the sheet, theink cannot be transferred to a recording paper if the sheet is mountedwith the wrong side out. Also, if the direction of winding is reversed,the sheet can not be wound up, resulting in a failure in printing.

SUMMARY OF THE INVENTION

In view of the above-described problem, therefore, it is an object ofthe invention to provide an ink ribbon cartridge capable of reliablypreventing the improper mounting of an ink ribbon.

In order to accomplish the above-described object, the ink ribboncartridge of the invention has a pair of spools, an ink ribbon includinga band-like sheet wound around the pair of spools and provided with alayer of ink formed on one surface thereof, four spindles which havedisk-shaped sections at one end and can be placed, for a specific lengthof the other end, in both ends of the pair of spools, and a covercovering the pair of spools around which the sheet is wound and havingfour round holes in which the disk-shaped sections of each of thespindles are loosely fitted.

The other end of a specific one of the four spindles can not be placedfor the specific length in three of the four ends of the pair of spools.In addition, three of the four round holes formed in the cover are madesuch that the disk-shaped section on one side of the specific spindlecan not be loosely fitted.

According to the ink ribbon cartridge of the invention, since the otherend of the specific one of four spindles can not fit for a specificlength in three of the four ends of a pair of spools, the other end of aspool in which one side of the specific spindle can be placed will beunequivocally determined. In addition, since the disk-shaped section onone side of the specific spindle can not be fitted in three of the fourround holes formed in the cover, the round hole in which the disk-shapedsection of the specific spindle can be loosely fitted will also beunequivocally determined. Consequently, both the mounting and windingdirections of the covered sheet will be unequivocally determined,thereby reliably preventing improper mounting of the ink ribbon.

To make is impossible to fit the other end of the specific one of fourspindles for a specific length into any one of three of the four ends ofa pair of spools, it is sufficient to provide a slot in the axialdirection in the end face of the spool and a projection on the spindlewhich is placed in this slot, and also to provide a longer slot in oneend face of a spool on one side and a longer projection on the spindleon one side that the other.

To make it impossible to loosely fit one side of the disk-shaped sectionof the specific spindle in three of four round holes formed in thecover, it is necessary to provide, for instance, a larger-diameterdisk-shaped section of the specific spindle than the disk-shaped sectionof the other spindles and also to increase the diameter of one of thefour round holes formed in the cover than that of the outer round holes.

Furthermore, according to another embodiment of the ink ribbon cartridgeof the invention, the ink ribbon cartridge has an ink ribbon including apair of spools and a band-like sheet wound around a pair of spools andprovided with a layer of ink formed on one side thereof, four spindleswhich have a disk-shaped section at one end and can be placed, for aspecific length of the other end, in the ends of the pair of spools; anda cover covering the pair of spools around which the sheet is wound, andhaving four round holes in which the disk-shaped section of each of thespindles is loosely fitted. In the ink ribbon cartridge, only a specificone of the four spindles can fit for the specific length in one of thefour ends of the pair of spools; and one of the four round holes formedin the cover is made such that the disk-shaped section of the specificspindle can be loosely fitted therein.

According to the ink ribbon cartridge of the invention, only the otherend of the specific one of four spindles can be placed for a specificlength in one of the four ends of a pair of spools; therefore, the otherend of the specific one of the four spindles is unequivocallydetermined. In addition, since only the disk-shaped section on one sideof the specific spindle can fit in one of the four round holes formed inthe cover, the round hole on the side in which the specific one of thespecific spindle can fit is also unequivocally determined. Therefore,the mounting and winding directions of the sheet within the cover areunequivocally determined, thus reliably preventing defective mounting ofthe ink ribbon.

To make it possible to fit the other end of the specific one of fourspindles for a specific length into only one of the four ends of a pairof spools, it is sufficient to provide a slot in the axial direction inthe end face of the spool and a projection on the spindle which isplaced in this slot, and also to provide a shorter slot in one end faceon one side of a spool and a shorter projection on one of the spindlesthan the others.

To make it possible to loosely fit only the disk-shaped section on oneside of the specific spindle in one of four round holes formed in thecover, it is necessary to provide, for instance, a smaller-diameterdisk-shaped section on one side of specific the spindle than thedisk-shaped section of the other spindles and also to decrease thediameter of one of the four round holes formed in the cover than that ofthe other round holes.

Furthermore, another embodiment of the ink ribbon cartridge of theinvention is similar to the ink ribbon cartridge discussed above,however two slots are formed in the circular end face of each of thefour ends of a pair of spools. The four spindles are each provided withtwo projections which can fit in a couple of slots in the spool. Thesetwo projections are provided on a specific one of the four spindles andare arranged at an angle different from other three spindles, withrespect to the axial center of the specific spindle. The two slotsformed in the end face of one of the four ends of the spools arearranged at an angle different from the other three ends with respect tothe center of the end face, so that two projections provided on aspecific spindle can be placed in the two slots.

The ink ribbon cartridge may be structured such that because of therelationship of placing the projection of the spindle in the slot of thespool, the specific one of the four spindles can not fit for a specificlength in three of the four ends of a pair of spools so that only theother end of a specific one of the four spindles can fit for a specificlength in a specific one of the four ends of the pair of spools.Furthermore, since the slots are formed in the spool body, the spool canbe more easily be manufactured as compared with a spool which isprovided with projections on the inner peripheral surface thereof.

Furthermore, another embodiment of the ink ribbon cartridge of theinvention is the ink ribbon cartridge as discussed above, however, withtwo of the four spindles having a gear section formed to rotate thespool on the axis. Because a gear section is formed on two spindles, thesheet can be taken up by turning the two spindles inserted in one end ofthe pair of spools. Therefore, it is possible to decrease the length inthe direction of the axis of the spool by the same amount as the widthof the gear section as compared with a cartridge having the gear sectionformed on each of the four spindles.

Furthermore, another embodiment of the ink ribbon cartridge of theinvention is the ink ribbon cartridge stated above and furtherstructured such that a round hole will be opened when the cover is in aclosed state; the gear section is larger in diameter than thedisk-shaped section and is positioned on the other end of the spindle;and when the end of the spindle on which the gear section is formed isinserted for a specific length in the wrong end of one of a pair ofspools, the gear section of the spindle is positioned in the round holein the cover, so that the cover will not close.

The ink ribbon cartridge of the invention has the following advantage,in that when the other end of the spindle on which the gear section isformed is placed for a specific length in either end of one of the pairof spools, the cover will not close because the gear section ispositioned in the round hole of the cover, thereby preventing defectiveinstallation, that is, the placement of two spindles with the gearsection into the same spool on one side of the cartridge.

Furthermore, another embodiment of the ink ribbon cartridge of theinvention is instructed such that the cover has two gear cover sectionsin which a gear section formed on either of the two spindles is looselyfitted, and can be opened and closed so that the gear cover section maybe formed when the cover is closed; on the four spindles are formeddisk-shaped collar sections which are larger in diameter than the insidediameter of the gear cover section of the cover; and when the spindlewith the gear section and the spindle without the gear section areplaced in mutually opposite positions in both ends of one of the pair ofspools, and the collar section on the spindle without the gear sectionis positioned in the gear cover section of the cover, the cover will notclose.

The ink ribbon cartridge has the following advantage, in that when thespindle with the gear section and the spindle without the gear sectionare positioned in mutually opposite directions in both ends of one ofthe pair of spools, the collar section of the spindle without the gearsection is positioned in the gear cover section of the cover to therebyprevent the cover from closing. It is, therefore, possible to preventimproper mounting of the spindle with the gear section and the spindlewithout the gear section on one specific side of a spool.

Furthermore, another embodiment of the ink ribbon cartridge of theinvention is structured such that, in the cover are formed two gearcover sections in which the gear sections formed on two spindles areloosely fitted; the cover operating so that the gear cover section willbe formed when the cover is closed; on each of the four spindles isformed a disk-shaped collar section which is larger in diameter than theinside diameter of the gear cover section of the cover, so that when thespindle with the gear section is placed in either end of one of the pairof spools, the collar section of one of the two spindles is positionedin the gear cover section of the cover to prevent the cover fromclosing.

The ink ribbon cartridge has the advantage that when the spindle withthe gear section is positioned in both ends of one of the pair ofspools, the collar section of one of the two spindles is positioned inthe gear cover section of the cover to prevent the cover from closing.It is, therefore, possible to prevent improper mounting, that is,fitting of two spindles with the gear section into the same spool.

According to the ink ribbon cartridge as explained above, since theother end of the specific one of four spindles can not fit for aspecific length in three of four ends of a pair of spools, the other endof a spool in which one side of the specific spindle can be placed willbe unequivocally determined; and also since the disk-shaped section onone side of the specific spindle can not be placed in three of the fourround holes formed in the cover, the round hole in the cover in whichone side of the specific spindle can be loosely fitted will also beunequivocally determined. Consequently, both the mounting and windingdirections of the sheet in the cover will be unequivocally determined,thereby reliably preventing improper mounting of the ink ribbon.

Also according to the ink ribbon cartridge of the invention, only theother end of the specific one of four spindles can be fitted for aspecific length in one of the four ends of a pair of spools; thereforethe other end of the specific one of the four spindles is unequivocallydetermined. In addition, since only the disk-shaped section on one sideof the specific spindle can fit in one of the four round holes formed inthe cover, the round hole in the cover in which one side of the specificone of the spindles can fit is also unequivocally determined.Consequently, the mounting and winding direction of the sheet within thecover are unequivocally determined, thus reliably preventing defectivemounting of the ink ribbon.

Furthermore, according to the ink ribbon cartridge of the invention, theink ribbon cartridge may be structured such that, because of therelationship between fitting the projections of the spindle in the slotsof the spool, the other end of the specific one of the four spindles cannot fit for a specific length in three of the four ends of a pair ofspools and only the other end of a specific one of the four spindles canfit for a specific length in one of the four ends of the pair of spools.Furthermore, since slots are formed in the spool body, the spool can bemore easily manufactured as compared with a spool which is provided withprojections on the inner peripheral surface thereof.

According to the ink ribbon cartridge of the invention, because a gearsection is formed on two spindles the sheet can be taken up by turning apair of spools with these two spindles inserted in one end of the pairof spools. Therefore, it is possible to decrease the length of the inkribbon cartridge in the direction of the axis of the spool by the sameamount as the width of the gear section as compared with a case wherethe gear section is formed on each of the four spindles.

Furthermore, the ink ribbon cartridge has the advantage that when theother end of the spindle on which the gear section is formed is placedfor a specific length in the wrong end of either one of the pair ofspools, the cover will not close because the gear section on one side ofthe spindle is positioned in the round hole of the cover, therebypreventing defective installation, that is, fitting of two spindles withgear sections into the same spool on one side of the ink ribboncartridge.

Furthermore, the ink ribbon cartridge has the advantage that when thespindle with the gear section and the spindle without the gear sectionare positioned in mutually opposite directions in both ends of one ofthe pair of spools, when the collar section of the spindle without thegear section is positioned in the gear cover section of the cover, thecover is prevented from closing. It is, therefore, possible to preventimproper mounting of the spindle with the gear section and the spindlewithout the gear section in a spool on one side of the ink ribboncartridge.

Furthermore, the ink ribbon cartridge of the invention has the followingadvantage, that when spindles with gear sections are positioned in bothends of one of the pair of spools, the collar section of the other oneof the two spindles is positioned in the gear cover section of the coveron the other side of the cartridge to prevent the cover from closing. Itis, therefore, possible to prevent improper mounting, that is, fittingtwo spindles with the gear section into the spool on one side of the inkribbon cartridge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an ink ribbon cartridge according to theinvention;

FIG. 2 is a front view of the ink ribbon cartridge shown in FIG. 1;

FIG. 3 is a bottom view of the ink ribbon cartridge shown in FIG. 1 inan opened position;

FIG. 4 is a bottom view of an ink ribbon mounted in the ink ribboncartridge shown in FIG. 1;

FIG. 5 is a front view of a spool provided in the ink ribbon cartridgeshown in FIG. 1;

FIG. 6 is a front view of another spool provided in the ink ribboncartridge shown in FIG. 1;

FIG. 7 is a front view of a spindle provided in the ink ribbon cartridgeshown in FIG. 1;

FIG. 8 is a side view of the spindle shown in FIG. 7;

FIG. 9 is a front view of another spindle provided in the ink ribboncartridge shown in FIG. 1;

FIG. 10 is a side view of the spindle shown in FIG. 9;

FIG. 11 is a front view of another spindle provided in the ink ribboncartridge shown in FIG. 1;

FIG. 12 is a side view of the spindle shown in FIG. 11; and

FIG. 13 is a bottom view of a cover in an opened position provided inthe ink ribbon cartridge shown in FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter preferred embodiments of a recording apparatus according tothe invention will be particularly explained with reference to theaccompanying drawings.

First, the ink ribbon cartridge for use in a recording apparatus will beexplained. FIG. 1 is a plan view of the ink ribbon cartridge accordingto the invention; FIG. 2 is a front view of the same; and FIG. 3 is abottom view thereof. In FIG. 3, the cover is in an opened position.

The ink ribbon cartridge 1 is made up of an ink ribbon 2, four spindles3 to 6, and a cover 7. The ink ribbon 2, as shown in FIG. 4, comprises apair of paper spools 21 and 22, and a band-like sheet 23 wound on thesespools 21 and 22. The spool 21 and the spool 22 are of the same shapeand size and are cylindrical in shape. The sheet 23 has a ink layer 23Aformed on one side of the entire surface of, for instance a resin film.With the sheet 23 inserted between the recording surface of a thermalprint head of a thermal printer (e.g., a line printer) and the recordingpaper, the current is supplied to the heating element of the thermalprint head in accordance with the image data, thereby forming image lineafter image line on the recording paper. At this time, the recordingpaper is positioned on the ink layer 23A side. On one end face 21A ofthe spool 21, as shown in FIG. 5, slots 24 and 25 of specific depth areformed in a radial direction. These slots 24 and 25 are arranged at aninterval of 180 degrees around the center of the axis of the spool 21.There are also formed slots similar to the slots 24 and 25 in the otherend face 21B of the spool 21 and in one end face 22A of the spool 22. Inthe other end face 22B of the spool 22, as shown in FIG. 6, slots 26 and27 of specific depth are formed in the radial direction. These slots 26and 27 are arranged at an interval of 150 degrees around the center ofthe axis of the spool 22.

The spindle 3 is unitarily molded of for instance a resin, and, as shownin FIGS. 7 and 8, consists of a small-diameter portion 31, a disk-shapedsection 32, a gear section 33, a disk-shaped collar section 34, and aspindle portion 35, which are arranged in the order of mention from oneend of the spindle to the other. The disk-shaped section 32 measureslarger in diameter than the small-diameter portion 31 and the spindleportion 35; the gear section 33 is larger in diameter than thedisk-shaped section 32; and the collar section 34 has a larger diameterthan the gear section 33. On the outer peripheral surface of one end ofthe spindle portion 35 are provided projections 36 and 37, which arearranged 180 degrees apart from each other around the center of the axisof the spindle portion 35. These projections 36 and 37 fit in the slots24 and 25 in one end face 21A of the spool 21 when the spindle portion35 of the spindle 3 is placed in one end of the spool 21. In the otherend of the spindle portion 35 are formed slots 38 and 39. The spindle 4is also of the same structure, shape and size as the spindle 3.

The spindle is unitarily molded of, for instance, a resin and, as shownin FIGS. 9 and 10, consists of a small-diameter portion 51, adisk-shaped section 52, a disk-shaped collar section 53, and spindleportion 54, which are arranged in the order of mention from one end ofthe spindle to the other. The disk-shaped section 52 is larger indiameter than the small-diameter portion 51 and the spindle portion 54,and the collar section 53 measures larger in diameter than thedisk-shaped section 52. On the outer peripheral surface of one endportion of the spindle portion 54 are provided projections 55 and 56,which are arranged 180 degrees apart from each other around the centerof the axis of the spindle portion 54. These projections 55 and 56 fitin slots in the other end face 21B of the spool 21 when the spindleportion 54 of the spindle 5 is placed in the other end of the spool 21.In the other end of the spindle portion 54 are formed slots 57 and 58.The spindle 5 is of the same shape and size as the spindle 3 includingthe disk-shaped section 32 and the collar section 34 but does notinclude the gear section 33.

The spindle 6 is unitarily molded of for instance, a resin, and, asshown in FIGS. 11 and 12, comprises a small-diameter portion 61, adisk-shaped section 62, a disk-shaped collar section 63, and a spindleportion 64, which are arranged in the order of mention from one end ofthe spindle towards the other. The disk-shaped section 62 has a largerdiameter than the small-diameter portion 61 and the spindle portion 64,and the collar section 63 has a larger diameter than the disk-shapedsection 62. On the outer peripheral surface of one end of the spindleportion 64 are projections 65 and 66, which are arranged 150 degreesapart from each other around the center of the axis of the spindleportion 64. These projections 65 and 66 fit in the slots 26 and 27 ofthe other end face 22B of the spool 22 when the spindle portion 64 ofthe spindle 6 is placed in the other end of the spool 22. In the otherend of the spool portion 64 are formed slots 67 and 68. The spindle 6 isa little smaller than the disk-shaped section 52 of the spindle 5 but isof the same shape and size. However, the spindle 6 includes theprojection 66 disposed 30 degrees closer to the projection 65.

The cover 7 is unitarily molded of, for example, a resin, and comprises,as shown in FIG. 13, a first cylindrical section 71, a secondcylindrical section 72, and connection sections 73 and 74. The firstcylindrical section 71 and the second cylindrical section 72 areconnected by the connecting sections 73 and 74. The first cylindricalsection 71 consists of an upper half section 75, a lower half section76, and a connecting section 77. The lower half section 76 is rotatableon the center of the connecting section 77. In one end wall of the upperhalf section 75 and the lower half section 76 are formed semi-circularrecesses 78 and 79. A round hole is formed by the recesses 78 and 79when the lower half section 76 is closed. The round hole formed by therecesses 78 and 79 is larger in diameter than the disk-shaped section 32of the spindle 3 and smaller in diameter than the gear section 33. Inthe vicinity of one end of the upper half section 75 and the lower halfsection 76 are formed partition walls 80 and 81. In these partitionwalls 80 and 81 are formed semi-circular recesses 82 and 83. When thelower half section 76 is closed, a round hole is formed by the recesses82 and 83. The round hold has a larger diameter than the gear section 33of the spindle 3 and has a smaller diameter than the collar section 34.Between the one end wall of the upper half section 75 and the lower halfsection 76 and the partition walls 80 and 81, a plurality of ribs 75Aand 76A protrude on the inner peripheral surface of the upper halfsection 75 and the lower half section 76. The projecting ends of theseribs 75A and 76A are flush with the end wall of the recesses 82 and 83formed in the partition walls 80 and 81. A space between the one endwall of the upper half section 75 and the lower half section 76 and thepartition walls 80 and 81 is nearly equal to the width of the gearsection 33, and the gear cover section covering the gear section 33 isformed by the one end wall of the upper half section 75 and the lowerhalf section 75, the partition walls 80 and 81, and the ribs 75A and76A.

In the other end wall of the upper half section 75 and the lower halfsection 76 are formed semi-circular recesses 84 and 85. When the lowerhalf section 76 is in a closed position, a round hole is formed by therecesses 84 and 85. The round hole made by the recesses 84 and 85 islarger in diameter than the disk-shaped section 52 of the spindle 5 andsmaller in diameter than the collar section 53.

The second cylindrical section 72 consists of an upper half section 86,a lower half section 87, and a connecting section 88. The lower halfsection 87 is rotatable from the center of the connecting section 88. Inone end wall of the upper half section 86 and the lower half section 87are formed semi-circular recesses 89 and 90. When the lower half section87 is in a closed position, a round hole is formed by the recesses 89and 90. The round hole formed by the recesses 89 and 90 has a largerdiameter than the disk-shaped section of the spindle 4 and a smallerdiameter than the gear section 33. In the vicinity of one end of theupper half section 86 and the lower half section 87 are formed partitionwalls 91 and 92. In these partition walls 91 and 92 are formedsemi-circular recesses 93 and 94. When the lower half section 87 is in aclosed position, a round hole is formed by the recesses 93 and 94. Theround hole measures larger in diameter than the gear section of thespindle 4 and smaller than the collar section. Between the one end wallof the upper half section 86 and the lower half section 87 and thepartition walls 91 and 92, a plurality of ribs 86A and 87A protrude onthe inner peripheral surface of the upper half section 86 and the lowerhalf section 87. The protruding ends of these ribs 86A and 87A are flushwith the end walls of the recesses 93 and 94 formed in the partitionwalls 91 and 92. A space between the one end wall of the upper halfsection 86 and the lower half section 87 is nearly equal to the width ofthe gear section of the spindle 4. Thus, the gear cover section coveringthe gear section of the spindle 4 is formed by the one end walls of theupper half section 86 and the lower half section 86, the partition walls91 and 92, and the ribs 86A and 87A.

In the other end walls of the upper half section 86 and the lower halfsection 87 are formed semi-circular recesses 95 and 96. When the lowerhalf section 87 is in a closed position, a round hole is formed by therecesses 95 and 96. The round hole formed by the recesses 95 and 96,measures larger in diameter than the disk-shaped section 62 of thespindle 6, and is smaller in diameter than each of the collar section63, the round hole formed by the recesses 78 and 79, the round holeformed by the recesses 84 and 85, and the round hole formed by therecesses 89 and 90.

On the other end of the first cylindrical section 71 is provided alocking member 101 for locking and releasing the lower half section 76with the upper half section 75, as shown in FIG. 2. The locking member101 comprises a projection 102 that protrudes from the other end face ofthe upper half section 75 and a locking section 103 that protrudes fromthe other end face of the lower half section 76. The locking section 103is secured at the lower end to the other end face of the lower halfsection 76, and bends toward the upper half section 75 to engage theprojection 102. When the projection 102 fits in the hole formed nearlyat center, the projection 102 engages with the locking section 103, thuslocking the lower half section 76 to the upper half section 75. On oneend face of the first cylindrical section 71 there is also provided alocking member similar to the locking member 101.

On the other end of the second cylindrical section 72 is provided alocking member 105 for locking and releasing the lower half section 87to the upper half section 86 as shown in FIG. 2. The locking member 105consists of a projection 106 that protrudes from the other end face ofthe upper half section 86, and a locking member 107 that protrudes fromthe other end face of the lower half section 87. The locking section 107is secured at the lower end to the other end face of the lower halfsection 87, and bends toward the upper half section 86 to engage theprojection 106. When the projection 106 fits in the hole formed nearlyat center, the projection 106 is engaged with the locking section 107,thus locking the lower half section 87 to the upper half section 86. Onone end face of the second cylindrical section 72 there is also provideda locking member similar to the locking member 105.

FIG. 3 shows the ink ribbon cartridge properly mounted with the spools21 and 22 of the ink ribbon 2 and with the spindles 3 to 6 inserted inthe spools when mounted in the cover 7. That is, the axial movement ofthe spool 21 is restricted by contact between the collar section 34 ofthe spindle 3 and the partition walls 80 and 81 of the upper halfsection 75 and the lower half section 76 of the first cylindricalsection 71, and also by contact between the collar section 53 of thespindle 5 and the other end walls of the upper half section 75 and thelower half section 76 of the first cylindrical section 71. The axialmovement of the spool 22 is restricted by contact between the collarsection of the spindle 4 and the partition walls 91 and 92 of the upperhalf section 86 and the lower half section 87 of the second cylindricalsection 72. The spool 22 and the spindles 4 and 6 make up a take-upspindle for taking up the sheet 23, and the spool 21 and the spindles 3and 5 make up a feed spindle for feeding the sheet 23.

To replace a used ink ribbon 2, the cover 7 is opened as shown in FIG.3, the used ink ribbon 2 is taken out, the spindles 3 to 6 are removedfrom the spools 21 and 22 of the used ink ribbon 2, and then thespindles 3 to 6 are installed to the spools 21 and 22 of the new inkribbon 2. That is, the spindle portion 35 of the spindle 3 is placed inone end of the spool 21; the spindle portion 54 of the spindle 5 isplaced in the other end of the spool 21; the spindle portion of thespindle 4 is placed in one end of the spool 22; and the spindle portion64 of the spindle 6 is placed in the other end of the spool 22. At thistime, as shown in FIG. 12, the projections 65 and 66 of the spindle 6are 150 degrees apart from each other around the axis of the spindleportion 64. Also, as shown in FIG. 6, since the slots 26 and 27 in theother end face 22B of the spool 22 are arranged 150 degrees apart fromeach other around the center of the axis of the spool 22, the spindleportion 64 of the spindle 6 can be placed only in the other end of thespool 22. That is, when the spindle portion 64 of the spindle 6 isplaced in one end or the other end of the spool 21 or in one end of thespool 22, the projection 65 comes into contact with the end face of thespool 21 or the spool 22 and can not be inserted any further beyond thisposition. In addition, when the spindle sections 35 and 54 of thespindles 3 to 5 are fitted in the other end of the spool 22, theprojections 36 and 55 or the projections 37 and 56 contact the end faceof the spool 22, and thereafter can not be inserted any further beyondthis position. Consequently, the inserting position of the spindle 6will be unequivocally determined. It is possible to identify the spindle6 from among the four spindles 3 to 6 according to the angle of theprojections 65 and 66, but this identification can be done more easilyby using a different color for the spindle 6 from other spindles 3 to 5,for example.

Furthermore, when the ink ribbon 2 is mounted to the cover 7, thespindle 6 will be set on the other end of the second cylindrical section72 because the round hole in the other end wall of the secondcylindrical section 72 is smaller than the round hole in either end wallof the first cylindrical section 71 and the round hole in one end wallof the second cylindrical section 72 and therefore only the disk-shapedsection 62 of the spindle 6 can be loosely placed in the round hole.That is, when the spindles 3 to 5 are positioned on the other side ofthe second cylindrical section 72, the round hole formed by the recesses95 and 96 of the upper half section 86 and the lower half section 87 ofthe second cylindrical section 72 is smaller in diameter than thedisk-shaped section 32 of the spindle 3 and the disk-shaped section 52of the spindle 5, the lower half section 87 can not be engaged with theupper half section 86 and the cover 7 can not be closed accordingly.Consequently, with the ink ribbon 2 set in the cover 7, the other end ofthe spool 22 is positioned on the other end side of the secondcylindrical section 72, and the ink ribbon 2 can be set in the propermounting and winding directions, accordingly.

In the meantime, the spindles 3 to 5 can be placed in both ends of thespool 21 and in one end of the spool 22. If, however, the spindles 3 and4 are inserted, for example, in the both ends of the spool 21, the spool21 becomes longer by the width of the gear section 33 than the spool ofwhich the spindles 3 and 5 are placed. Therefore, the lower half section76 of the first cylindrical section 71 can not be engaged with the upperhalf section 75. That is, let us suppose that when the disk-shapedsection of the spindle 4 is placed in the recess 84 in the other endwall of the upper half section 75 of the first cylindrical section 71,the collar section 34 of the spindle 3 is positioned between one endwall of the upper half section 75 and the partition wall 80. In thisposition, the rib 75A is provided on the upper half section 75 and therib 76A is provided on the lower half section 76. Therefore, when thelower half section 76 is engaged with the upper half section 75, theinside diameter of the gear cover section comprising the one end wall ofthe upper half section 75 of the first cylindrical section 71, thepartition wall 80, the rib 75A and the rib 76A is smaller than thediameter of the collar section 34 of the spindle 3. Therefore when thecollar section 34 of the spindle 3 is disposed between the one end wallof the upper half section 75 and the partition wall 80, the cover 7 cannot be closed.

In addition, when the collar section 34 of the spindle 3 is held incontact with the partition wall 80 of the upper half section 75 of thefirst cylindrical section 71, the gear section of the spindle 4 ispositioned in the recess 84 in the other end wall of the upper halfsection 75 of the first cylindrical section 71. The round hole formed bythe recess 84 of the upper half section 75 and the recess 85 of thelower half section 76 is smaller in diameter than the gear section ofthe spindle 4 and therefore the lower half section 76 of the firstcylindrical section 71 can not be engaged with the upper half section75, and therefore the cover 7 can not be closed.

Furthermore, when the spindle 5 is fitted in one end of the spool 21 andthen the spindle 3 in the other end of the spool 21, for example, thecollar section 53 of the spindle 5 will be positioned in the gear coversection on one end of the first cylindrical section 71. Consequently, itbecomes impossible to engage the lower half section 76 of the firstcylindrical section 71 with the upper half section 75 and the cover 7can not be closed.

If the spindles 3 to 6 are properly set in the spools 21 and 22 and thespools 21 and 22 thus assembled are not properly set in the cover 7, thecover 7 can not be closed. It is, therefore, possible to reliablyprevent defective setting of the ink ribbon 2. The spindle 3 and thespindle 4, being of the same shape and size, may be mutually changed inposition without causing any inconvenience.

While this invention has been described in conjunction with specificembodiments thereof, it is evident that many alternative, modifications,and variations will be apparent to those skilled in the art.Accordingly, preferred embodiments of the invention as set forth hereinare intended to be illustrative, not limiting. Various changes may bemade without departing from the spirit and scope of the invention asdescribed in the following claims.

1. An ink ribbon cartridge, comprising: an ink ribbon including aband-like sheet with a layer of ink formed on one surface thereof; apair of spools for holding the ink ribbon, each of the pair of spoolshaving two ends, two end faces and a hole formed in each of the twoends, wherein two slots are formed in each end face of the pair ofspools; and four spindles each having one end including a disk-shapedsection, and an other end, wherein each of the other ends of the fourspindles are seated in the holes formed in the ends of the pair ofspools; wherein the other end of a specific one of the four spindles cannot be seated in the holes formed in the ends of three of four ends ofthe pair of spools, and the other ends of the other three of the fourspindles can not be properly seated in the hole formed in the end of aspecific one of four ends of the pair of spools.
 2. The ink ribboncartridge of claim 1, wherein each of the four spindles have twoprojections which fit in the two slots formed in each in each end faceof the pair of spools.
 3. The ink ribbon cartridge of claim 2, whereinthe two projections provided on the specific one of the four spindlesare arranged at a different angle from the other three spindles, withrespect to an axial center of the specific spindle.
 4. The ink ribboncartridge of claim 3, wherein the two slots formed in a specific endface of one of the pair of spools are arranged at a different angle fromthe slots formed in the other end faces of the pair of spools withrespect to a center of the end faces and the two projections provided onthe specific one of the four spindles are so formed as to be fitted inthe two slots formed in the specific end face of one of the pair ofspools.
 5. An ink ribbon cartridge, comprising: an ink ribbon includinga band-like sheet with a layer of ink formed on one surface thereof; apair of spools for holding the ink ribbon, each of the pair of spoolshaving two ends, two end faces and a hole formed in each of the twoends; and four spindles each having one end including a disk-shapedsection, and an other end, wherein each of the other ends of the fourspindles are seated in the holes formed in the ends of the pair ofspools; wherein the other end of a specific one of the four spindles cannot be properly seated in the holes formed in the ends of three of thefour ends of the pair of spools, and the other ends of the other threeof the four spindles can not be seated in the hole formed in the end ofa specific one of the four ends of the pair of spools.
 6. The ink ribboncartridge of claim 5, wherein each end of the pair of spools has twoslots, and each of the four spindles has two projections which fit inthe two slots.
 7. The ink ribbon cartridge of claim 6, wherein the twoprojections on the specific one of the four spindles are arranged at adifferent angle from the other three spindles, with respect to an axialcenter of the specific spindle.
 8. The ink ribbon cartridge of claim 7,wherein the two slots formed in a specific end face of one of the pairof spools are arranged at a different angle from the slots formed in theother end faces of the pair of spools with respect to a center of theend faces and the two projections provided on the specific one of thefour spindles are so formed as to be fitted in the two slots formed inthe specific end face of one of the pair of spools.
 9. A printcartridge, comprising: a cartridge body having: a first roll holdingsection having a first half section, a second half section pivotallyconnected along one longitudinal edge to the first half section by aconnection section, a locking element on each end of the first rollholding section to lock the first half section to the second halfsection to close the first roll holding section, each half sectionhaving closed ends with an axially aligned recess, the recesses definingan axially aligned hole in each end of the first roll holding sectionwhen the first half section and the second half section are closed, theholes in both ends of the first roll holding section having the samediameter; a second roll holding section having a first half section, asecond half section pivotally connected along one longitudinal edge tothe first half section by a connection section, a locking element oneach end of the first roll holding section to lock the first halfsection to the second half section to close the second roll holdingsection,, each half section having closed ends with an axially alignedrecess, the recesses defining an axially aligned hole in each end of thesecond roll holding section when the first half section and the secondhalf section are closed, the hole in a first end of the second rollholding section having a diameter equal to the diameter of the holes inthe first end and second end of the first roll holding section and thehole in a second end of the second roll holding section having adifferent diameter; a connection structure having a first connectionmember extending from the first end of the first half section of thefirst roll holding section to the first end of the first half section ofthe second roll holding section and a second connection member extendingfrom the second end of the first half section of the first roll holdingsection to the second end of the first half section of the second rollholding section; a plurality of spindles; and a ribbon assemblycomprising: a first spool; a second spool; and an ink ribbon rolled onthe first spool and attached to the second spool to be taken up thereon,the first spool comprising a first hollow tube, a first spindle of theplurality of spindles mounted to a first end of the first hollow tubeand a second spindle of the plurality of spindles mounted to a secondend of the first hollow tube; the second spool comprising a secondhollow tube, a third spindle of the plurality of spindles mounted to afirst end of the second hollow tube and a fourth spindle of theplurality of spindles mounted to a second end of the second hollow tube,the first and third spindles being identical and each having a spindleportion received in a respective first end of a one of the first hollowtube and the second hollow tube, a disk-shaped collar section, a gearsection, a disk-shaped section and a small diameter portion away fromthe hollow tube, the second and fourth spindles having a spindle portionreceived in a second end of a respective one of the first hollow tubeand the second hollow tube, a disk-shaped collar section, a disk-shapedsection and a small diameter portion away from the hollow tube, thedisk-shaped section of the fourth spindle having a different diameterthan the disk-shaped section of the second spindle.
 10. The printcartridge according to claim 9, wherein the cartridge body is oneintegral piece.
 11. The print cartridge according to claim 9, whereinthe diameter of the hole in the second end of the second roll holdingsection is less than the diameter of the holes in the first end of thesecond roll holding section and in both ends of the first roll holdingsection.
 12. The print cartridge according to claim 11, wherein thediameter of the disk-shaped section of the fourth spindle is less thanthe diameter of the disk-shaped section of the second spindle.
 13. Theprint cartridge according to claim 9, wherein the fourth spindle isdistinguished by a different color than the first, second and thirdspindles.
 14. The print cartridge according to claim 9, furthercomprising a partition wall in each of the first half section and thesecond half section of the both the first roll holding section and thesecond roll holding section interiorly separated from the closed firstends, the partition walls having axial recesses and connected to theclosed first ends of the first roll holding section and the second rollholding section by ribs extending between the partition walls and theclosed first ends.
 15. An ink ribbon cartridge, comprising: a cartridgebody having a feed housing and a take-up housing, the feed housing andthe take-up housing each having a first section and a second sectionpivotally joined by a connecting section, axial end walls of the firstsection and the second section each having a recess so that when thefeed housing and the take-up housing are closed axially aligned holesare formed in each axial end wall, the first section and the secondsection further having a partition wall offset from and connected to anadjacent axial end wall at one end by ribs, a recess formed in thepartition wall being larger than the recess formed in the axial end wallfrom which offset, the recesses in the partition walls of the firstsection and the second section when closed defining a gear hole; lockingmembers on an exterior surface of the axial end walls for locking thefirst section to the second section of each of the feed housing and thetake-up housing; a connecting member extending from each axial end ofthe first section of the take-up housing to a corresponding axial end ofthe first section of the feed housing; a plurality of spindlescomprising: two gear spindles, each gear spindle having a spindle end, acollar, a gear, a disk-shaped section having a first size and a smalldiameter section in sequence, extending from the spindle portion andadjacent the collar are two projections offset from one another by 180°;a feed spindle having a spindle portion, a collar, a disk-shaped sectionof the first size, and a small diameter portion, extending from thespindle portion and adjacent the collar are two projections offset fromone another by 180°; and a take-up spindle having a spindle portion, acollar, a disk-shaped section having a second size, and a small diameterportion, extending from the spindle portion and adjacent the collar aretwo projections offset from one another at an angle different than 180°;and a ribbon assembly comprising: a hollow feed spool having a pair ofslots in each end, the slots off-set by 180°, and a hollow take-up spoolhaving a pair of slots in each end, the slots at one end being off-setby 180°, the slots at the other end being off-set at the angle otherthan 180°, wherein a gear spindle is received in the one end of each ofthe feel spool and the take-up spool, the gear of each gear spindlebeing seated in the gear hole of a respective one of the feed housingand the take-up housing, the take-up spindle being received in the otherend of the take-up spool with the disk-shaped section seated in the holedefined by the recesses in the first section and the second section ofthe take-up housing and the feed spindle seated in the other end of thefeed spool with the disk-shaped section seated in the hole defined bythe recesses in the first section and the second section of the feedhousing.
 16. An ink ribbon cartridge, comprising: a cartridge frame; afirst spindle, a second spindle, a third spindle and a fourth spindle,each of the first, second, third and fourth spindles being rotatablysupported by the cartridge frame; a first spool having a first end and asecond end, the first end engaging the first spindle and the second endengaging the second spindle; a second spool having a third end and afourth end, the third end engaging the third spindle and the fourth endengaging the fourth spindle; and an ink ribbon supported on the firstspool and the second spool; wherein: when the first, second, third andfourth spindles engage the first, second, third and fourth ends,respectively, the ink ribbon, spools and spindles are configured forprinting; the first spindle is capable of engaging the first end, but isnot capable of engaging the second, third and fourth ends; and thesecond, third and fourth spindles are capable of engaging the second,third and fourth ends, but are not capable of engaging the first end.17. The ink ribbon cartridge of claim 16, wherein each of the spindlescomprises a resin.
 18. The ink ribbon cartridge of claim 16, whereineach of the ends comprises an end face, a hole for receiving a spindle,and two slots formed in the end face.
 19. The ink ribbon cartridge ofclaim 18, wherein each of the spindles comprises a disk-shaped sectionand an end section for insertion into the hole of arespective end. 20.The ink ribbon cartridge of claim 19, wherein each of the end sectionscomprises two projections for insertion into the two slots of arespective end.
 21. The ink ribbon cartridge of claim 20, wherein: thetwo projections of the first spindle are situated at a first angle withrespect to each other about an axis of rotation of the first spindle;the two slots of the first end are situated at the first angle withrespect to each other about an axis of rotation of the first spool; thetwo projections of the second spindle are situated at a second anglewith respect to each other about an axis of rotation of the secondspindle; the two slots of the second end are situated at the secondangle with respect to each other about the axis of rotation of the firstspool; the two projections of the third spindle are situated at thesecond angle with respect to each other about an axis of rotation of thethird spindle; the two slots of the third end are situated at the secondangle with respect to each other about an axis of rotation of the secondspool; the two projections of the fourth spindle are situated at thesecond angle with respect to each other about an axis of rotation of thefourth spindle; the two slots of the fourth end are situated at thesecond angle with respect to each other about the axis of rotation ofthe second spool; and the first angle is different from the secondangle.
 22. The ink ribbon cartridge of claim 21, wherein the first angleis about 150° and the second angle is about 180°.
 23. The ink ribboncartridge of claim 16, wherein at least one of the spindles comprises agear portion.
 24. The ink ribbon cartridge of claim 16, wherein thecartridge frame comprises a resin.
 25. The ink ribbon cartridge of claim16, wherein the cartridge frame comprises a first cover portion that atleast partially covers the first spool.
 26. The ink ribbon cartridge ofclaim 16, wherein the cartridge frame comprises a second cover portionthat at least partially covers the second spool.
 27. The ink ribboncartridge of claim 16, wherein the ink ribbon comprises a band-likesheet with a layer of ink formed on one surface thereof.
 28. The inkribbon cartridge of claim 27, wherein the band-like sheet comprises aresin.